As integrated circuit (IC) device and substrate feature sizes continue to shrink in the semiconductor industry, as well as the increased use of 3D devices structures in IC designs (e.g., Intel's Tri-Gate transistor architecture), the capability of depositing thin conformal films (films of material having a uniform thickness relative to the shape of the underlying structure, even if non-planar) will continue to gain importance. Atomic layer deposition (ALD) is a film forming technique which is well-suited to the deposition of conformal films due to the fact that a single cycle of ALD only deposits a single thin layer of material—a result of the ALD process involving the formation of an adsorption-limited layer of one or more film precursor reactants prior to the film-forming surface reaction of the precursors. Multiple “ALD cycles” may then be used to build up a film of the desired thickness, and since each layer is thin and conformal, the resulting film substantially conforms to the shape of the underlying substrate features and/or device structures.
However, there are many challenges associated with employing ALD processes in semiconductor fabrication, oftentimes relating to the fact that many ALD cycles are required to build up a film of appreciable thickness. Rapid ALD cycle times may be facilitated by specialized semiconducting processing hardware, however, without careful design of these deposition apparatuses and the film forming operations performed in them, the uniformity of the resulting ALD films may be compromised. Accordingly, methods and apparatuses are sought which improve the uniformity of films deposited via ALD and related processes.